Fernández Noroña tweeted about his incursion, saying roughly, "I'm very satisfied with today's protest. Only two of us did it, requiring no more than our determination and patriotism".
Fernández Noroña was accompanied by a woman who broadcast the protest on the Periscope app using her cellphone.
The protest isn't remarkable for its content: protests against Trump's policies were a staple of his candidacy and rallies, and have continued even since his election.
But what is remarkable is that a foreign politician can now make his objections publicly deep inside what has already been labelled "White House North" in some quarters.
He didn't protest outside the White House fence. He didn't gather protesters on the Mall. He walked right into Trump's building, and sat down in front of the lifts. His message was broadcast to the pool of media outlets that has cameras at Trump Tower every day, snapped in photos by newspaper and wire photographers, and written about by print reporters, all in front of the backdrop of Trump's shiny golden home.
New York City is footing a huge bill to keep Trump Tower secure - the lobby of Trump Tower is considered a public space, and must be accessible to the public during certain hours each day.
In early December, a man was arrested for entering the lobby carrying knives and fireworks. Just last week, the lobby was evacuated due to a suspicious bag (that turned out to be filled with children's toys).
Trump seems to have no plans to move out of his golden New York home long-term. And his wife and youngest son will remain there, at least for the early months of his presidency.
But as long as the President-elect (and soon-to-be-president) keeps one of his primary residences in downtown Manhattan, there are likely to be security challenges - and maybe the occasional protest from a foreign dignitary.
